Origin Of Natural Gas And Natural Gas Accumulation From Middle-shallow Layer In South Songzhan

The South of Songzhan is on the northern of Yushulin oil field,it is located in the Northeast slope of Central Depression of SongliaoBasin-Sanzhao Depression,next to Shengping Construction in the West,Songzhan Nose-like structure in the North,Shangjia Nose-like structure in the East,Xujiaweizi Construction Group in the Sorth.at the present, Shengping, Wangjiatun,Songzhan,Yushulin,Shangjia oil and gas field in Putaohua and Fuyang oil layers in the mid-shallow formation of Sanzhao have been found around Study area,however,at the present,the exploration in South Songzhan is still relatively low,geological understanding of a very shallow,the prospects for oil and gas resources not very clear.Chemical composition and isotopic composition which are the only Geochemical data of natural gas are the main causes when it comes to the origin of natural gas.Based on methane,heavy hydrocarbons,non-hydrocarbon and carbon isotopes and other aspects of comparative study on natural gas,we have reached the conclution that natural gas in the shallow part of Song Nan is homologous that in Shengping region and they both contion but little inorganic gas.baseed on the analysis and comparation of natural gas in shallow and deep part of Shengping area ,it is concluted that natural gas, weather shallow or deep source,enjoy the same origion.through the study of source rocks in deep part in Shengping region,we arrived the conclution that deep natural gas in Shengping region mainly from sub-group of Shahe. So natural gas in shallow and Moderate part of Song Nan mainly from sub-group of Shahe. Shallow and Moderate part of Song Nan mainly oil floors are Putaohua and Fuyang oil layers.Putaohua reservoir is mainly underwater distributary channel sand, sand dams,and I like sand to the hole in the main penetration. Fuyang reservoir main dam for the river sand and sand to the middle-low porosity and ultra-low-low-mainly the non-permeability reservoirs.the main migration conduit channel of natural gas in shallow and Moderate part of Song Nan is faulted period of depression a view to continuing the activities of the formation of the fractureand Period of the formation of rift tectonic inversion phase Depression period and the activities of the fracture.These faults of the underlying communication sub-group of Shahe valid source rocks and traps in the shallow strata of the effective. Putaohua and Fuyang oil layers in this area mainly are by fault block trap primarily.